The screws should go fully in and be tightened, this may cause the clutch to drag, if the plates have been corked with thick corks !, but better than leaving them loose as they will work out and form a gouge or deep radial groove in the inner chaincase or worse !Best to use automatic gearbox fluid in the clutch case ( TQF/ATF)JH

Yes screws have to be fully home and locked or they will gradually work themselves out and hit the inner case, TQF is fine with bonded plates, it is the set up I always ran on my Villiers engine trials bikes and they get a lot more stick than you are going to do .JH